I don't think it's reasonable to say that because only 10% of drivers are reckless, we don't get to regulate the other 90% along with them. Of course if we had some magical wand that would tell us who the reckless drivers are, then we could only target the dangerous folks, but often that's impossible.

Often the best we can do is take a look at the data and see what kind of policies would not be horribly burdensome for the general public and yet would save a lot of lives, and then we institute those.

The other part of the problem with the 10% bad drivers argument is that bad drivers change from hour to hour, and from day to day. After all, the majority of people believe that they're good drivers, right?